Optically sized fonts, was, re: [XeTeX] Font strangeness

[Jonathan Kew]

On 24 May 2005, at 8:02 am, Will Robertson wrote:

> On a related matter, I was wondering if anyone has a multiple master 
> font with optical scaling they could lend me *strictly* for the 
> purposes of developing and testing fontspec so that [OpticalSize=] 
> works for both OpenType fonts with discrete optical sizes and MM fonts 
> with continuous ones. (If indeed it's possible to combine the two into 
> a single feature.)

The problem you'll be up against here is that the only way to get MM 
axis support in XeTeX is via the ATSUI-based text engine, which exposes 
MM axes just like AAT variations. But then you won't have the OpenType 
feature support that's provided via the ICU Layout engine.

Under Tiger, I suppose some of the OpenType layout features may be 
available through the ATSUI interface as well--I have done very limited 
experimentation so far. But the OT support in Tiger's ATSUI is 
considerably weaker than the ICU version; only a limited selection of 
features are supported, and not all lookup types work, for example. 
Nor, of course, is there any complex-script shaping.

Of course, given that Adobe is no longer promoting MM fonts, perhaps 
the existing ones are all old enough that they don't have OT Layout 
features anyway....

JK